1. Field of the Invention
This invention relates to a process for the regeneration of perovskite-containing catalysts and use of the regenerated catalysts in hydrocarbon treating processes, particularly in hydrocarbon cracking processes.
2. Description of the Prior Art
The use of perovskite-containing catalysts for hydrocarbon treating processes is known. U.S. Pat. No. 4,208,269 and U.S. Pat. No. 4,179,409 disclose perovskite catalysts and their use in hydrocarbon conversion processes.
U.S. Pat. No. 4,055,513 and U.S. Pat. No. 4,102,777 disclose high surface area perovskite catalysts and their use in hydrocarbon conversion processes.
In various processes for the conversion of hydrocarbons in the presence of a catalyst, a hydrocarbonaceous material (coke) deposits on the catalyst thereby causing at least a partial deactivation of the catalyst. For example, in catalytic cracking processes, it is well known to withdraw the partially deactivated (coked) catalyst from the catalytic cracking zone and to regenerate the coked catalyst by combustion of the carbonaceous deposit at an elevated temperature at oxidizing conditions to form oxides of carbon and steam. The regenerated catalyst, which may still comprise a residual carbonaceous deposit which has not been completely removed, is then recycled to the catalytic cracking zone.
It is known to use high temperature regeneration to effect more complete removal of the carbonaceous deposit, that is, to obtain a catalyst having a residual coke level of less than 0.05 weight percent on catalyst from deactivated catalysts. See, for example, U.S. Pat. No. 3,909,392.
It has now been found that the rate of combustion of carbon on a coked catalyst can be increased at relatively low regeneration temperatures when the catalyst comprises a perovskite.